ICU: the elasticity of demand

The intensive care units are the most expensive health system resources, and it’s logical that both the funders and the general public wonder whether the way these are used meets their full potential. But, despite this interest the data in this area are sadly rather scarce. Of the few that I have had access to, I will highlight two: a) the variations are impressive: in the US the cost of ICU represent 1% of GDP, while in the UK only 0.1%, ten times less b) misuse, or if you prefer - therapeutic obstinacy towards the end of life of people with chronic diseases- is detected; continuing in the United States, it’s estimated that between 13% and 35% of chronic patients die in an ICU, or they die in a hospital bed after being admitted to the critical care unit (J. Wennberg. Tracking Medicine. Oxford University Press, 2010).

Two intensive carers at the University of Pittsburgh, Dr. Rebecca Gooch and Dr. Jeremy Kahn, published in JAMA a conceptual model on the elasticity of demand for ICU admissions. In a 2x2 table they’re showing the severity of the disease crossed with  the chances of survival.

To the top left of the graph, the target population for ICU admission is framed: sick complex patients with potential to succeed and, conversely, to the lower right is the population that should never enter a critical care unit: chronic and fragile patient in a stage towards the end of life. In the other two quadrants, little complexity with real chances of survival (angor pectoris) and very complex patients but towards the end stage of life (irreversible traumatic coma), are the two types of patients who will be admitted only if there are beds available, and that's what the authors compare with the elasticity of demand, such as when a highway is expanded with a new lane, but surprisingly, withholding at peak times does not improve because there are people who, given the new resource, abandons public transport and takes the car to go to work.

In accord to the conceptual model of the elasticity of demand, strategies to adjust the hospitalization of patients in critical care units should meet the following criteria:

1. Adjusting the number of ICU beds to the case-mix of complex patients with chances of survival.
2. Avoiding the admission of chronic patients, especially towards the end of their lives.
3. Dimensioning nursing observation units for patients who, despite having special needs, do not meet the requirements of the target model.

To advance in this line of good clinical practice, it’s necessary to evaluate, much more than we do now, the adequacy of admissions in critical care units, especially with the aim of reducing the waste of resources, but also to avoid causing unnecessary suffering for people who maybe would receive a more appropriate care in other care institutions.


Jordi Varela

Editor